MATLAB Function Reference |

**Syntax**

**Description**

```
S = speye(m,n)
```

forms an `m`

-by-`n`

sparse matrix with `1`

s on the main diagonal.

```
S = speye(n)
```

abbreviates `speye(n,n)`

.

**Examples**

`I`

`=`

`speye(1000)`

forms the sparse representation of the 1000-by-1000 identity matrix, which requires only about 16 kilobytes of storage. This is the same final result as `I`

`=`

`sparse(eye(1000,1000))`

, but the latter requires eight megabytes for temporary storage for the full representation.

**See Also**

`spalloc`

, `spones`

, `spdiags`

, `sprand`

, `sprandn`

spdiags | spfun |